Pumps come in various designs depending on their operating requirements and the environment in which they will be used. One type of pump assembly that has been developed utilizes two separate housings which are operably connected to each other by magnets. One housing contains a drive motor and is designed to be placed outside of a container. A second housing is placed inside of the container and is held in place through a magnetic connection with the first housing. The drive motor rotates a magnet located in the first housing. The magnet of the first housing is magnetically coupled to a magnet in the second housing, so that the magnet in the second housing rotates with the magnet in the first housing. The magnet in the second housing is connected to a propeller or an impeller to impart movement to fluid in the container.
Magnetically coupled pumps have mainly been used in aquariums and provide a number of advantages over prior devices. Magnetically coupled pumps may be placed in any location on a container without concern over a mechanical mount. The attraction force of the magnets through the container wall holds the pump in place, eliminating the need to place holes in the container. The elimination of brackets or other mechanical fasteners reduces the amount of used materials and the overall weight of the pump. Mechanical fasteners may fracture or break, resulting in an otherwise operable pump becoming inoperable or less efficient because it cannot be held in a proper position. A magnetically coupled pump also eliminates the need for electrical components to be submerged in water, eliminating the need to seal the motor housing, resulting in a smaller and lighter pump.